Condensation on baseboard by sliding doors...

Hi all,

I live in a 30-year-old condominium. I am going to put engineered-wood flooring in the living room with an underlay.

The living room is now carpeted. But I have a bit of a problem. There is a sliding door leading to the balcony. During the winter months ice forms on the floor and the sides of the wall where the metal sliding frame meets the floor and the wall. This concerns me as I don't want ice to damage the floor and trim which I intend to install.

I have taken some pictures of how it looks now with the carpet. There is a bit of a 4 inch separation between the sliding door frame and floor. It is covered with carpet. I lifted the carpet end up and saw that there is a wood board fastened to the wall under the sliding door frame.

You see, I peeled back the carpet, and found this old, wood board:

Here is my intended solution. I take out the carpet and the wood board under the sliding door. I put in EITHER some Pink Fibreglass OR 300 Polystyrene Rigid Installation board and glue it to the wall, where the wood board used to be. I then cover this with a new wood board and then finally, I cover the wood with a long, 4 inch board of drywall, put on the mud, and sand, paint, prime. Then I go ahead and complete the engineered flooring installation.

So I have some questions:

1) Does it sound good?

2) Should I use the loose pink fibreglass or a fibreglass rigid installation insulation board?

3) Do I have to provide some space for the pink fibreglass to shrink or expand? Do I have to provide space for BOTH scenarios, that is, whether I use the loose pink fibreglass or the pink fibreglass board installation?